Commit e44524405796bf6bc27455e90dc9a86eb9a616c1
2019-05-09T13:29:49
Fix integer cube map sample HLSL calculation This patch fixes two issues in the HLSL generated to sample an integer cube map. The first issue was that an inappropriate major axis was selected when sampling from corners of the cube map. In particular, the added test case demonstrates a situation where a major axis of length 0 was selected, which lead to an infinite LOD being calculated. The fix was to adjust inequalities such that always exactly one of xMajor, yMajor and zMajor is true. The second issue was that the derivative functions ddx and ddy were being used on values that depended on the choice of major axis, which is not continuous at the corners of a cube map. This lead to a finite but incorrect LOD being calculated. The fix was to make sure major axis choice is not included when estimating the scaling factor. Bug: angleproject:3442 Change-Id: Ia3eb8c89f47d1bfdadc18aec989e8cbebc088ec0 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1601515 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>